Adding nanoparticles to water increase its thermal conductivity, or its ability to take heat away from something, which could save the world a significant amount of electricity. “In a world where the cost of coolth is a significant economic drain (industrial cooling consumes 7% of the electricity generated within the European Union) nanoparticles offer a worthwhile gain. It would, for instance, allow the huge computer-filled warehouses that drive the Internet to fit in more servers per square metre of floor space.”